996 REPORT—1885. 
simply the Borderland shales and greywackes in an altered state.!| Hence Nicol, 
equally with Murchison, was prepared to accept the Silurian age of the Durness 
limestone, and of the rocks associated with it. 
Murchison, still full of his old enthusiasm for discovery, determined to lose no ~ 
time in putting to the test the truth of the suggestion made by his old friend Nicol 
and himself; and accordingly shortly before the meeting of the British Association, 
which was fixed to take place in the year 1855 at Glasgow, we find the two friends 
making their way into the wild district of North-west Sutherland. 
Unfortunately the time was too short and the weather too unpropitious for the 
tasks they had set before themselves. 
When this Geological Section assembled at Glasgow, Murchison declared his 
conviction that the limestone of Durness, which had yielded the fossils to Mr. 
Peach, was of Silurian—that is, as he employed the term, of Lower Paleozoic 
age. But he, at the same time, maintained the truth of his old views, that the 
red sandstones of Applecross and Gareloch are in reality nothing but Old Red 
Sandstone,” and in this latter contention he received the warm support of Sedg- 
wick, who was also present at the meeting.’ 
Nicol, on the other hand, appears to have been greatly dissatisfied with the 
results of this hasty and inauspicious journey to Sutherland. While, however, 
withholding his judgment as to the age of the several rock-masses, he insisted, in 
opposition to the views of Murchison and Sedgwick, that the whole of the vast 
series of Red Sandstones in Applecross and Torridon is, as Macculloch showed, 
inferior to the quartzite and limestone.+* 
In the summer of the next year, 1856, Nicol, so soon as he was released from 
his teaching work in this university, hastened back to the Western Highlands to 
try and resolve some of the doubts which troubled him concerning the age and 
succession of the strata. This summer’s labour was productive of great and im- 
portant discoveries. In the first place, he was able to completely confirm the 
conclusion of Macculloch and Hay Cunningham, that al/ the Red Sandstone of the 
Western Highlands, with the exception of some small patches of ‘ New Red,’ belong 
to an old formation underlying the quartzite and limestone. But his researches 
also enabled him to show that Macculloch’s ‘ Primary Red Sandstone’ in reality 
consists of two formations, the lower—to which he subsequently gave the name of 
the ‘ Torridon Sandstone "—lying unconformably on the gneiss, and the upper (con- 
sisting of quartzite and limestone, containing fossils), resting everywhere uncon- 
formably upon, and overlapping, the sandstones.? It isa yery noteworthy circum- 
stance that while Nicol admitted the accuracy of the descriptions of Macculloch 
and Hay Cunningham which seemed to point to a conformable superposition of 
beds of gneiss to the quartzite and limestone, the results of this first summer’s work 
had already raised serious misgivings in his mind as to the correctness of this 
conclusion, for he wrote as follows :—‘ The fact of the overlying gneiss having been 
metamorphosed zz situ, and not pushed up over the quartzite, is one requiring further 
inyestigation.’® It is not surprising, however, to find that Nicol was so staggered 
by the magnitude of the faults which would be required to brmg about such a result, 
that for more than a year he hesitated to accept this, which we now know to be 
the true explanation of the phenomena. 
There was a suggestion—and it was nothing more than a suggestion—made 
by Nicol at this time, which has often been very unfairly quoted to his dis- 
advantage. Convinced that Macculloch was right as to the infraposition of the 
Torridon Sandstone to the quartzite and limestone, and strongly inclined to accept 
‘ Guide to the Geology of Scotland (1844). 
2 Brit. Ass. Rep. 1855 ; Trans. of Sec. p. 87. 
% Geikie’s Memoir of Sir Roderick Murchison (1875), vol. ii. p. 207. 
4 See Nicol’s Geology of the North of Scotland (1866), Appendix, p. 96. 
5 Col. Sir Henry James is said to have made similar observations during the same 
season, the summer of 1856, and to have communicated them to Sir Roderick 
Murchison by letter. But there can be no doubt that Nicol’s discovery was made 
quite independently, and he was the first to publish it. 
§ Quart. Journ, Geol. Soc. vol. xiii. (1857), p. 35. 
